One piece connectors for substrates or circuit boards having high edge contact density, such as 0.050 inch center-to-center spacing, exist in the from of a card-edge connector, but their proliferation is impeded by reliability problems experienced by the industry.
While the performance of a 0.050 inch card edge connector is marginal, any spacing denser than 0.050 inch makes a card-edge connector impractical because of registration problems and poor contact performance.
The spacing, within a single row, of contact centers measuring 0.050 inch and less, such as 0.0375 inch is the development to which this invention specifically but not exclusively relates.
A two piece connector is desirable for such a dense spacing because it allows a permanent mounting of the circuit board in a pluggable connector through soldering or press-fit, thus shifting the disconnect interface to male and female contact mating means.
An edge-mount packaging approach, in combination with an extremely high density mounting of contacts in a connector, is one object of this invention. The present connector is best utilized in applications where size and speed of equipment are major considerations and two piece connector reliability is required.
In edge-mount packages, as contrasted to face-mount packages such as Dual In-Line packages (DIP's), larger ceramic wafers could be used very effectively, without increasing the interconnection length between any two circuits on the motherboard and allowing larger cavities for hybrid components so as to obtain more functions per package.
This invention provides a high contact density two piece connector, one piece of which, having replaceable male contacts, is permanently solder or press-fit mounted on a motherboard or a wiring panel, and the other piece, having receptacle contacts, accepts an edge-mount semiconductor package or a similar panel member and exists as a disconnect module.
Another object of the invention is to provide a simple and versatile resilent coupling contact means which can be formed with an extremely small pitch and adapted to numerous applications by providing suitable extensions to the mating means.
One such extension to the male contact is a solder or a press-fit tail. For the female or receptacle contact a cantilever tab terminal means for resilently receiving a module package board is suitable.
The tails of successive male contacts are alternately rotated 180.degree. in the housing to plug into an offset hole pattern in the circuit board. The mating blades are aligned in a single line for mating with the receptacle contacts, which also have mating portions in a single straight line.
The receptacle contacts could also be installed in the insulator housing alternately rotated 180.degree., the contacts in such case having unequal substrate receiving cantilever tabs, the shorter of the two making contact to the lower circuit pad and the longer tab reaching the higher pad with savings of space resulting from the staggering utilized to increase pad width.
Such an increase in pad width is desired because it provides improved registration and relaxed tolerancing.
A still further object of the invention is to provide high module board retention by driving the board between the two rows of metal cantilever tabs extending upwardly from the receptacle means and outwardly above the insulator housing, registering with high pressure on the package pads and permitting infra-red reflow soldering, visual inspection of registration, and on-duty contact probing.
One cantilever tab of each common pair makes electrical contact with the pad on the component side of the package substrate, the other tab providing back-up means and, if desired, serving as a jumper to the circuitry on the other side of the substrate.
The term "substrate" as used in this specification broadly encompasses ceramic substrates, circuit boards, flexible circuits or cable, or any panel member provided with electrical conductors in either wired or printed form.